125. Valid Palindrome.py

class Solution(object):
    def isPalindrome(self, s):
        left = 0
        right = len(s)-1

        while(left<right):
            if not s[left].lower().isalnum():
                left+=1
                continue
            if not s[right].lower().isalnum():
                right-=1
                continue
            if s[left].lower()!=s[right].lower():
                return False

            left+=1
            right-=1

        return True